This disclosure relates to a touch panel which enables a user to input information by bringing a user's finger etc. into contact therewith or bringing the same in proximity thereto. In particular, the disclosure relates to a display device with a touch detection function, of a type which detects the contact or the proximity based on a change in an electrostatic capacitance.
In recent years, attention has been drawn to a display device in which a contact detector, generally referred to as a touch panel, is mounted on a display such as a liquid crystal display, and which allows the display to display various button images etc. to thereby make it possible to input information instead of providing typical mechanical buttons. There are a number of types of touch panels, including such as an optical type and a resistance type. In devices such as a portable handheld terminal, in particular, there are high expectations for a touch panel of an electrostatic capacitance type. The electrostatic capacitance touch panel has a relatively simple configuration, and is capable of reducing power consumption.
Japanese Unexamined Patent Application Publication No. 2009-244958 (JP2009-244958A) discloses a display device with a touch detection function, in which the electrostatic capacitance touch panel is incorporated in the liquid crystal display device. The display device with the touch detection function disclosed therein is provided with a pixel electrode used for displaying an image, a touch detection electrode used for detecting a touch, and a drive electrode (a common electrode) shared by the pixel electrode and the touch detection electrode. JP2009-244958A discloses an embodiment where a plurality of drive electrodes, extending in a horizontal direction and divided in a perpendicular direction, are used (FIG. 5 of JP2009-244958A).